#include "stdio_impl.h"
#include <errno.h>
#include <ctype.h>
#include <limits.h>
#include <string.h>
#include <stdarg.h>
#include <stddef.h>
#include <stdlib.h>
#include <wchar.h>
#include <inttypes.h>

/* Convenient bit representation for modifier flags, which all fall
 * within 31 codepoints of the space character. */

#define ALT_FORM   (1U<<'#'-' ')
#define ZERO_PAD   (1U<<'0'-' ')
#define LEFT_ADJ   (1U<<'-'-' ')
#define PAD_POS    (1U<<' '-' ')
#define MARK_POS   (1U<<'+'-' ')
#define GROUPED    (1U<<'\''-' ')

#define FLAGMASK (ALT_FORM|ZERO_PAD|LEFT_ADJ|PAD_POS|MARK_POS|GROUPED)

/* State machine to accept length modifiers + conversion specifiers.
 * Result is 0 on failure, or an argument type to pop on success. */

enum {
    BARE, LPRE, LLPRE, HPRE, HHPRE, BIGLPRE,
    ZTPRE, JPRE,
    STOP,
    PTR, INT, UINT, ULLONG,
    LONG, ULONG,
    SHORT, USHORT, CHAR, UCHAR,
    LLONG, SIZET, IMAX, UMAX, PDIFF, UIPTR,
    DBL, LDBL,
    NOARG,
    MAXSTATE
};

#define S(x) [(x)-'A']

static const unsigned char states[]['z'-'A'+1] = {
    { /* 0: bare types */
        S('d') = INT, S('i') = INT,
        S('o') = UINT, S('u') = UINT, S('x') = UINT, S('X') = UINT,
        S('e') = DBL, S('f') = DBL, S('g') = DBL, S('a') = DBL,
        S('E') = DBL, S('F') = DBL, S('G') = DBL, S('A') = DBL,
        S('c') = CHAR, S('C') = INT,
        S('s') = PTR, S('S') = PTR, S('p') = UIPTR, S('n') = PTR,
        S('m') = NOARG,
        S('l') = LPRE, S('h') = HPRE, S('L') = BIGLPRE,
        S('z') = ZTPRE, S('j') = JPRE, S('t') = ZTPRE,
    }, { /* 1: l-prefixed */
        S('d') = LONG, S('i') = LONG,
        S('o') = ULONG, S('u') = ULONG, S('x') = ULONG, S('X') = ULONG,
        S('e') = DBL, S('f') = DBL, S('g') = DBL, S('a') = DBL,
        S('E') = DBL, S('F') = DBL, S('G') = DBL, S('A') = DBL,
        S('c') = INT, S('s') = PTR, S('n') = PTR,
        S('l') = LLPRE,
    }, { /* 2: ll-prefixed */
        S('d') = LLONG, S('i') = LLONG,
        S('o') = ULLONG, S('u') = ULLONG,
        S('x') = ULLONG, S('X') = ULLONG,
        S('n') = PTR,
    }, { /* 3: h-prefixed */
        S('d') = SHORT, S('i') = SHORT,
        S('o') = USHORT, S('u') = USHORT,
        S('x') = USHORT, S('X') = USHORT,
        S('n') = PTR,
        S('h') = HHPRE,
    }, { /* 4: hh-prefixed */
        S('d') = CHAR, S('i') = CHAR,
        S('o') = UCHAR, S('u') = UCHAR,
        S('x') = UCHAR, S('X') = UCHAR,
        S('n') = PTR,
    }, { /* 5: L-prefixed */
        S('e') = LDBL, S('f') = LDBL, S('g') = LDBL, S('a') = LDBL,
        S('E') = LDBL, S('F') = LDBL, S('G') = LDBL, S('A') = LDBL,
        S('n') = PTR,
    }, { /* 6: z- or t-prefixed (assumed to be same size) */
        S('d') = PDIFF, S('i') = PDIFF,
        S('o') = SIZET, S('u') = SIZET,
        S('x') = SIZET, S('X') = SIZET,
        S('n') = PTR,
    }, { /* 7: j-prefixed */
        S('d') = IMAX, S('i') = IMAX,
        S('o') = UMAX, S('u') = UMAX,
        S('x') = UMAX, S('X') = UMAX,
        S('n') = PTR,
    }
};

#define OOB(x) ((unsigned)(x)-'A' > 'z'-'A')

union arg
{
    uintmax_t i;
    long double f;
    void *p;
};

static void pop_arg(union arg *arg, int type, va_list *ap)
{
    switch (type) {
           case PTR:    arg->p = va_arg(*ap, void *);
    break; case INT:    arg->i = va_arg(*ap, int);
    break; case UINT:    arg->i = va_arg(*ap, unsigned int);
    break; case LONG:    arg->i = va_arg(*ap, long);
    break; case ULONG:    arg->i = va_arg(*ap, unsigned long);
    break; case ULLONG:    arg->i = va_arg(*ap, unsigned long long);
    break; case SHORT:    arg->i = (short)va_arg(*ap, int);
    break; case USHORT:    arg->i = (unsigned short)va_arg(*ap, int);
    break; case CHAR:    arg->i = (signed char)va_arg(*ap, int);
    break; case UCHAR:    arg->i = (unsigned char)va_arg(*ap, int);
    break; case LLONG:    arg->i = va_arg(*ap, long long);
    break; case SIZET:    arg->i = va_arg(*ap, size_t);
    break; case IMAX:    arg->i = va_arg(*ap, intmax_t);
    break; case UMAX:    arg->i = va_arg(*ap, uintmax_t);
    break; case PDIFF:    arg->i = va_arg(*ap, ptrdiff_t);
    break; case UIPTR:    arg->i = (uintptr_t)va_arg(*ap, void *);
    break; case DBL:    arg->f = va_arg(*ap, double);
    break; case LDBL:    arg->f = va_arg(*ap, long double);
    }
}

static void out(FILE *f, const wchar_t *s, size_t l)
{
    while (l-- && !(f->flags & F_ERR)) fputwc(*s++, f);
}

static int getint(wchar_t **s) {
    int i;
    for (i=0; iswdigit(**s); (*s)++) {
        if (i > INT_MAX/10U || **s-'0' > INT_MAX-10*i) i = -1;
        else i = 10*i + (**s-'0');
    }
    return i;
}

static const char sizeprefix['y'-'a'] = {
['a'-'a']='L', ['e'-'a']='L', ['f'-'a']='L', ['g'-'a']='L',
['d'-'a']='j', ['i'-'a']='j', ['o'-'a']='j', ['u'-'a']='j', ['x'-'a']='j',
['p'-'a']='j'
};

static int wprintf_core(FILE *f, const wchar_t *fmt, va_list *ap, union arg *nl_arg, int *nl_type)
{
    wchar_t *a, *z, *s=(wchar_t *)fmt;
    unsigned l10n=0, fl;
    int w, p, xp;
    union arg arg;
    int argpos;
    unsigned st, ps;
    int cnt=0, l=0;
    int i;
    int t;
    char *bs;
    char charfmt[16];
    wchar_t wc;

    for (;;) {
        /* This error is only specified for snprintf, but since it's
         * unspecified for other forms, do the same. Stop immediately
         * on overflow; otherwise %n could produce wrong results. */
        if (l > INT_MAX - cnt) goto overflow;

        /* Update output count, end loop when fmt is exhausted */
        cnt += l;
        if (!*s) break;

        /* Handle literal text and %% format specifiers */
        for (a=s; *s && *s!='%'; s++);
        for (z=s; s[0]=='%' && s[1]=='%'; z++, s+=2);
        if (z-a > INT_MAX-cnt) goto overflow;
        l = z-a;
        if (f) out(f, a, l);
        if (l) continue;

        if (iswdigit(s[1]) && s[2]=='$') {
            l10n=1;
            argpos = s[1]-'0';
            s+=3;
        } else {
            argpos = -1;
            s++;
        }

        /* Read modifier flags */
        for (fl=0; (unsigned)*s-' '<32 && (FLAGMASK&(1U<<*s-' ')); s++)
            fl |= 1U<<*s-' ';

        /* Read field width */
        if (*s=='*') {
            if (iswdigit(s[1]) && s[2]=='$') {
                l10n=1;
                nl_type[s[1]-'0'] = INT;
                w = nl_arg[s[1]-'0'].i;
                s+=3;
            } else if (!l10n) {
                w = f ? va_arg(*ap, int) : 0;
                s++;
            } else goto inval;
            if (w<0) fl|=LEFT_ADJ, w=-w;
        } else if ((w=getint(&s))<0) goto overflow;

        /* Read precision */
        if (*s=='.' && s[1]=='*') {
            if (isdigit(s[2]) && s[3]=='$') {
                nl_type[s[2]-'0'] = INT;
                p = nl_arg[s[2]-'0'].i;
                s+=4;
            } else if (!l10n) {
                p = f ? va_arg(*ap, int) : 0;
                s+=2;
            } else goto inval;
            xp = (p>=0);
        } else if (*s=='.') {
            s++;
            p = getint(&s);
            xp = 1;
        } else {
            p = -1;
            xp = 0;
        }

        /* Format specifier state machine */
        st=0;
        do {
            if (OOB(*s)) goto inval;
            ps=st;
            st=states[st]S(*s++);
        } while (st-1<STOP);
        if (!st) goto inval;

        /* Check validity of argument type (nl/normal) */
        if (st==NOARG) {
            if (argpos>=0) goto inval;
        } else {
            if (argpos>=0) nl_type[argpos]=st, arg=nl_arg[argpos];
            else if (f) pop_arg(&arg, st, ap);
            else return 0;
        }

        if (!f) continue;
        t = s[-1];
        if (ps && (t&15)==3) t&=~32;

        switch (t) {
        case 'n':
            switch(ps) {
            case BARE: *(int *)arg.p = cnt; break;
            case LPRE: *(long *)arg.p = cnt; break;
            case LLPRE: *(long long *)arg.p = cnt; break;
            case HPRE: *(unsigned short *)arg.p = cnt; break;
            case HHPRE: *(unsigned char *)arg.p = cnt; break;
            case ZTPRE: *(size_t *)arg.p = cnt; break;
            case JPRE: *(uintmax_t *)arg.p = cnt; break;
            }
            continue;
        case 'c':
            if (w<1) w=1;
            if (w>1 && !(fl&LEFT_ADJ)) fprintf(f, "%*s", w-1, "");
            fputwc(btowc(arg.i), f);
            if (w>1 && (fl&LEFT_ADJ)) fprintf(f, "%*s", w-1, "");
            l = w;
            continue;
        case 'C':
            fputwc(arg.i, f);
            l = 1;
            continue;
        case 'S':
            a = arg.p;
            z = a + wcsnlen(a, p<0 ? INT_MAX : p);
            if (p<0 && *z) goto overflow;
            p = z-a;
            if (w<p) w=p;
            if (!(fl&LEFT_ADJ)) fprintf(f, "%*s", w-p, "");
            out(f, a, p);
            if ((fl&LEFT_ADJ)) fprintf(f, "%*s", w-p, "");
            l=w;
            continue;
        case 'm':
            arg.p = strerror(errno);
        case 's':
            if (!arg.p) arg.p = "(null)";
            bs = arg.p;
            for (i=l=0; l<(p<0?INT_MAX:p) && (i=mbtowc(&wc, bs, MB_LEN_MAX))>0; bs+=i, l++);
            if (i<0) return -1;
            if (p<0 && *bs) goto overflow;
            p=l;
            if (w<p) w=p;
            if (!(fl&LEFT_ADJ)) fprintf(f, "%*s", w-p, "");
            bs = arg.p;
            while (l--) {
                i=mbtowc(&wc, bs, MB_LEN_MAX);
                bs+=i;
                fputwc(wc, f);
            }
            if ((fl&LEFT_ADJ)) fprintf(f, "%*s", w-p, "");
            l=w;
            continue;
        }

        if (xp && p<0) goto overflow;
        snprintf(charfmt, sizeof charfmt, "%%%s%s%s%s%s*.*%c%c",
            "#"+!(fl & ALT_FORM),
            "+"+!(fl & MARK_POS),
            "-"+!(fl & LEFT_ADJ),
            " "+!(fl & PAD_POS),
            "0"+!(fl & ZERO_PAD),
            sizeprefix[(t|32)-'a'], t);

        switch (t|32) {
        case 'a': case 'e': case 'f': case 'g':
            l = fprintf(f, charfmt, w, p, arg.f);
            break;
        case 'd': case 'i': case 'o': case 'u': case 'x': case 'p':
            l = fprintf(f, charfmt, w, p, arg.i);
            break;
        }
    }

    if (f) return cnt;
    if (!l10n) return 0;

    for (i=1; i<=NL_ARGMAX && nl_type[i]; i++)
        pop_arg(nl_arg+i, nl_type[i], ap);
    for (; i<=NL_ARGMAX && !nl_type[i]; i++);
    if (i<=NL_ARGMAX) return -1;
    return 1;

inval:
    errno = EINVAL;
    return -1;
overflow:
    errno = EOVERFLOW;
    return -1;
}

int vfwprintf(FILE *restrict f, const wchar_t *restrict fmt, va_list ap)
{
    va_list ap2;
    int nl_type[NL_ARGMAX] = {0};
    union arg nl_arg[NL_ARGMAX];
    int olderr;
    int ret;

    /* the copy allows passing va_list* even if va_list is an array */
    va_copy(ap2, ap);
    if (wprintf_core(0, fmt, &ap2, nl_arg, nl_type) < 0) {
        va_end(ap2);
        return -1;
    }

    FLOCK(f);
    fwide(f, 1);
    olderr = f->flags & F_ERR;
    f->flags &= ~F_ERR;
    ret = wprintf_core(f, fmt, &ap2, nl_arg, nl_type);
    if (f->flags & F_ERR) ret = -1;
    f->flags |= olderr;
    FUNLOCK(f);
    va_end(ap2);
    return ret;
}
